Flexible tube and method of manufacture

ABSTRACT

A package and method of making and filling it in the form of a tubular flexible bag of laminated plastic sheet material with a dispensing fitment including a spout and a removable closure mechanically fastened to a flat wall at one end of the tubular bag with the method of making the filled package being continuous starting with a flat sheet of material and ending with a filled and closed package.

This application claims the benefit of Provisional application Ser. No.60/158,555, filed Oct. 8, 1999.

FIELD OF THE INVENTION

This invention relates to packaging and more particularly to tubularbags and fitments for such bag tubes together with the method of makingand filling such packages.

BACKGROUND OF THE INVENTION

Bag tubes are flexible packages, which combined many of the advantagesof bags and tubes for packaging of liquid and paste products.

The dispensing of product from prior art tubular packages typically isafforded by providing for tearing away a portion of the bag tube, forexample, at a corner edge or to provide a dispensing spout which isbonded to a wall of the bag.

It would be desirable to form a dispensing spout which can bemechanically fastened to a wall of the tubular container.

Prior art bag tubes typically are formed with a flexible wall or gussetat one end of the bag which extends between the front and back panelsmaking up the tubular body of the package and forms the bottom of theclosed tube which forms a base to support the filled flexible bag in anupright position. In the present invention, a fitment forming adispensing spout is installed in the end wall which now becomes the topof the finished and filled package.

The fitment itself is provided with a flange which extends for the fullthickness of the package and acts to support the flexible end wallduring manufacture and also during dispensing of contents of the packageby the ultimate consumer.

Aside from the advantages of such packages from the standpoint ofmarketing, shipping and storage, it is highly desirable that thepackages be made and filled in a continuous process starting with a rollof film from which the package is shaped, filled and sealed in a singlecontinuous operation. Such an inline production method eliminates theneed for prefabrication of tubes with storage of a supply until readyfor use.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a bag tube and a method ofmaking and filling it in a continuous process and in which the bag tubeis formed with a dispensing spout and screw type closure which makes itpossible to open and close the package without the need to empty all thecontents.

Another object of the invention is to provide a bag tube having an endprovided with a fitment affording a dispensing spout and closure whichpermits dispensing and resealing of the contents remaining in thepackage.

Another object of the invention is to provide a fitment for a bag tubewhich facilitates installation during manufacture and use of theflexible package by the ultimate consumer.

These and other objects of the invention are attained by the presentinvention in which a pair of opposed panels of flexible plasticlaminated material have a pair of opposed sealed edges and a sealedbottom portion to form a flat tube closed at one end. The closed end ofthe tube extends between the panels and supports a fitment including adispensing nozzle and a detachable closure which is mechanicallyfastened to the end wall by means of an anchor member inserted throughthe open end of the package and threadably engage with the nozzleportion of the fitment. The fitment itself is provided with an elongatedflange which extends diametrically of the passage in the spout for thefull width of the filled package to engage opposite sides of the packageto resist torque during manufacture and to facilitate handling of thepackage by the consumer during opening and closing of the spout.

BRIEF DESCRIPTION O THE DRAWINGS

FIG. 1 is a perspective view of a bag tube package made in accordancewith the method of the invention;

FIG. 2 is a cross-sectional view at an enlarged scale showing thefitment with a pouring spout and closure at one end of the bag tube;

FIG. 3 is a bottom view of one of the elements of the fitment in FIG. 2;

FIG. 4 is a diagrammatic, perspective view of a horizontal bag-makingmachine employing the method of the present invention;

FIG. 5 is a diagrammatic, cross-sectional view of the folded material atone stage of the method of forming a bag tube;

FIG. 6 is an elevation of a partially formed bag tube in a flatcondition;

FIG. 7 is a bottom view of the package shown in FIG. 6 in an open orunfolded condition of the bag tube;

FIG. 8 is an edge view of the bag with the bottom unfolded as seen inFIG. 7;

FIG. 9 is a side view with parts broken away and removed showing therelative position of parts at one of the stages of forming the bag tubepackage;

FIG. 10 is a view similar to FIG. 9 showing the fitment installed in thepartially completed package; and

FIG. 11 is a top view of the partially finished bag tube in an opencondition ready for filling.

DETAILED DESCRIPTION

The finished and filled bag tube embodying the invention is designatedgenerally at 10 in FIG. 1 and includes a pair of opposed walls 12 ofplastic material which are sealed together at opposite side edges 14 toform a tubular structure which when filled has a generally ovalcross-section. The bottom of the package is heat sealed similarly to theside edges 14 to form an elongated bottom seam 16. The upper end of thetube package 10 is formed with a flat wall or gusset 18 which supports afitment 20. An edge portion 19 is formed at the top of the walls 12 atthe perimeter of gusset 18.

As seen in FIG. 1, the fitment 20 includes a tubular spout 22 having anelongated flange or plate 24 at one end which extends the full thicknessof the filled package 10. Opposite ends of the plate 24 are formed withtabs 26 which extend from the plate opposite to the spout to engageopposite sides of the upper end of package 10. Referring to FIG. 2, theplate end of spout 22 is provided with internal threads 32 in a passage30 to receive an anchor or plug element 34. Anchor element 34 includesan externally threaded stem or tube 36 having an annular flange 38 atone end. Anchor element 34 is positioned inside the tubular packagemember to pass through an opening 40 in the wall or gusset 18 tothreadably engage the internal threads 32 in spout 22. With threads 36and 32 tightly engaged, the film material around the opening 40 istrapped between the flange 38 of the plug or anchor 34 and the plate 24of the fitment 20.

An internally threaded cap 28 can be threadably mounted on theexternally threaded spout 22 to close the axial passage 30 in the spout22. The entire fitment assembly, including the spout 22, cap 28 andanchor element 34, can be made of plastic.

The construction of the bag tube 10 is similar in many respects to themaking of pouch type packages described in Laudenberg U.S. Pat. No. 5,845,466. Referring to FIG. 4, a continuous sheet of film 42 ofpreprinted, laminated plastic film is stored on a supply roll 44 and isdispensed through a forming mechanism 48 at opposite surfaces of thesheet 42 which folds the sheet material into a cross-sectionalconfiguration as shown in FIG. 5 so that portions of one sheet surfaceface each other. As seen in FIG. 5, at the bottom of the folded sheet, afolded portion 52 extends upwardly between opposed outer portions 54 sothat a fold line 53 is formed centrally of the gusset 18. Also a pair offold lines 55 are formed at the bottom of outer portions 54 to form theedges 19 of the gusset 18 as seen in FIG. 1. The facing surface of thesheet material is a sealant surface of a plastic material which respondsto heat to fuse and bond together with a surface of like material. Heatis applied by way of heat sealant bars indicated diagrammatically at 56in FIGS. 4 and 5 to opposite sides of the web assembly to fuse the sideedges 14 and bottom portions 58 as shown in FIG. 6 to form a partial bagtube 60. Subsequently, the bag tubes 60, which remained attached to eachother, pass between rolls 62 which apply pressure to opposite sides toinsure that the heated surfaces bond to each other. Thereafter, thepartially completed tubes are cut from the adjoining sheet material byshears 64 and are transferred to a first workstation. Preferably thefirst station is formed on a rotating turret 66 which can consist ofeight stations 71-78 making it possible to simultaneously conduct eightdifferent operations on eight bags.

The turret 66 may have one or more sets of grippers 80 at each stationas disclosed in U.S. Pat. No. 5,845,466. In FIG. 4 grippers areindicated only at station 71. As seen in FIG. 4, at a first station 71,a pair of grippers 80 grasp opposite side edges of the flat tube 60 nearthe open end of the partially formed tube 60 so that the gusset end 18is disposed downwardly. Upon rotation of turret 66 to a second station72, the grippers 80 are moved mechanically toward each other to open thetube so that the partially completed package 60 has a generallyelliptical cross-section as viewed from the top as seen in FIG. 11. Alsothe bottom of the tube 60 is unfolded as seen in FIG. 8 so that thegusset 18 is at its full width and at right angles to the walls 12 ofthe partially formed bag tube 60.

After the tube 60 is opened at the second station 72, it is moved to thenext station 73, where the opening 40 is die cut in the bottom wall orgusset 18 and the cut material is removed. The die cutter may berobotically operated.

The turret 66 is then rotated to a fourth station 74 where a tubularspout 22 forming a part of fitment 20 is placed under opening 40 ingusset 18. The spout 22 has a closure 28 already in place and ispositioned so that the plate 24 extends across the width of the gusset18 with the tabs 26 extending upwardly towards the open end of the tube60.

The turret 66 is rotated and at a fifth station 75 the anchor element 34is introduced through the open end of the partially formed tube 60 by arobotic arm (not shown). To facilitate handling, the anchor element 34is provided with a plurality of ribs 81 on the interior wall of tube 36as seen in FIG. 3. The ribs 81 facilitate handling of the anchor element34 during manipulation in the bag tube 60. The anchor element 34 ismoved downwardly so that the externally threaded tube 36 passes throughopening 40 to engage the internal threads 32 in the axial passage 30 ofthe tubular spout 22. The ribs 81 facilitate application of torque toanchor element 34 during twisting of the threads of tube 36 relative tothe stationary internal threads in tubular spout 22 to tightly engagethe film material of the partially formed bag tube 60 and capture thematerial surrounding the die cut opening 40 between the annular flange38 of the anchor element 34 and the plate element 24 at the end oftubular spout 22. The gusset end 18 of the tubular package is nowcompletely closed.

Upon rotation of the turret 66 to the next station 76, the product to bepackaged is fed into the upper, open end of the tube 60 which remainsheld by the grippers 80. After the tube 60 is filled with product, thegrippers 80 arc moved apart to close the upper end of the tube 60. Theturret 66 is then rotated to the next station 77 where heat-sealingelements can be moved to engage opposite side edges of the upper end offilled tube 60 and form the seam 16. The turret 66 can then be rotatedto the last station 78 where the grippers 80 are open to release thefilled package 10 for transfer to additional handling equipment such asconveyors and the like by which the filled packages 10 are moved forfurther packaging in cartons for shipment.

A bag tube, fitment and method of forming and filling such a bag tubehave been provided for packaging paste materials, cosmetics and the likewhich is lighter in weight and less costly to produce. The methodeliminates the need to have a cap-closing machine since the spoutfitment is supplied with a cap such as a tamper evident cap already inposition. The bag tube is provided with a fitment affording a dispensingspout closed with a threaded closure. The fitment acts to reinforce theflexible closed end of the flexible bag tube and facilitate manufactureand subsequent use. The method provides for producing the pouch in asingle operation and no inventory of empty tubes is necessary. Thematerial of plastic laminate permits flexography or gravure printing.

I claim:
 1. A flexible tubular package with a dispensing spout at oneend comprising: a pair of opposed panels having sealed opposed sideedges to form a tube, a bottom edge of said panels being fused togetherto form a closed tube, an end of said tube having an end wall extendingbetween said panels, a fitment secured to said end wall including adispensing spout forming a dispensing passage normal to the outsidesurface of said end wall, said spout having threads formed in saiddispensing passage, and an anchor member disposed at the inside surfaceof said wall for engagement with said fitment to hold the latter insealing engagement with said wall, said anchor member having anexternally threaded stem engaging said threads of said dispensingpassage.
 2. The combination of claim 1 wherein said end wall is flexibleand formed of the same material as said panels.
 3. The package of claim1 wherein a removable closure is disposed on said nozzle spout.
 4. Thepackage of claim 1 wherein said opposed panels and said end wall areformed of a single sheet of material.
 5. The package of claim 4 whereinsaid single sheet of material is folded and said closed edges and endwall are heat-sealed.
 6. The package of claim 1 wherein said spout hasan elongated flange extending between and engaging said panels.
 7. Themethod of forming and filling a flexible, tubular package having aclosable pouring spout, comprising: forming a flexible, tubular packagewith an open end and a wall forming a closed end, forming an aperture insaid wall, positioning a fitment with a spout having an internallythreaded passage extending between a pair of open ends and a plate atone end larger than said aperture adjacent to said wall at the exteriorof s aid package and in alignment with said aperture, inserting ananchor member having a threaded stem and an annular flange larger thansaid aperture into said package through said open end with said stem insaid aperture and into engagement with said threaded passage, rotatingsaid anchor member relative to said fitment to engage said threads onsaid anchor member with the threads in said passage to draw said annularflange and said plate into sealed engagement with opposed surfaces ofsaid wall at said closed end of said tubular package, filling saidpackage with a product, and sealing said open end of said package. 8.The method of claim 7, wherein said tubular package is formed of a sheetof flat plastic material and wherein a pair of side edges and saidclosed end of said package are formed by applying heat to said closedend and side edges.
 9. The method of claim 7, wherein said tubularpackage is flat initially and said package is moved to an open positionprior to forming said aperture in said wall at said closed end.
 10. Themethod of claim 7, wherein said ends of said tubular package are movedto an open position by moving opposite side edges of said package towardeach other.
 11. The method of claim 7, wherein said aperture is formedby die cutting and the cut material is removed from said aperture at theexterior of said package.
 12. The method of claim 7, wherein saidpackage has its open end moved to a closed position by moving oppositeside edges of said tube away from each other after said tube is filled.13. The method of claim 12, wherein said open end of said package isheat sealed after said opposed side edges have been moved away from eachother.
 14. The method of claim 7, wherein said anchor member is rotatedrelative to said fitment to engage said threads and move said annularflange and plate into sealing engagement with opposed surfaces of saidwall.
 15. The method of claim 7, wherein said tubular package is formedby folding a single sheet of plastic foil and applying heat to oppositesides of said sheet to seal opposed edges and to form said closed end.